Promotional flash drives are manufactured in Shenzhen China and branded with a company logo, then given away as a promotional item, usually for free at conventions or to employees.
These flash drives are often programmed to report the wrong capacity. For example 8GB when there is only a 2GB memory chip. The drive will work fine until you store more than 2GB of data.
Sometimes you’ll get mystery components like in this case where the flash drive was actually a MicroSD card reader. Check out this video of a promotional flash drive we received for recovery that was actually a MicroSD card reader.